Enhancing Mechanical Energy Transfer of Piezoelectric Supercapacitors

Abstract The expected widespread use of wearable and other low‐power healthcare devices has triggered great interest in piezoelectric materials as a promising energy harvester. However, traditional piezoelectric materials suffer from poor interfacial energy transfer when used in self‐charging power cells. Herein, piezoelectric supercapacitors (PSCs) are engineered using MXene‐incorporated polymeric piezo separator and MXene (Ti₃C₂T_x) multilayered sheets as electrodes. The MXene‐blended polymer film showed considerable improvement with maximum output voltage of 28 V and current of 1.71 µA. The electromechanical properties studied by piezoelectric force microscopy suggest that the integration of MXene in polyvinylidene fluoride (PVDF) matrix induces the degree of dipole moment alignment, thereby improving the piezoelectric properties of PVDF. At the device level, the PSC featured the capacitance of 61 mF cm^–2, the energy density of 24.9 mJ cm⁻², the maximum power density of 1.3 mW cm⁻³, and the excellent long‐term cycling stability. A way is paved toward green, integrated energy harvesting and storing technology for next‐generation self‐powered implantable and wearable electronics.